1. Technical Field
The disclosure relates to a touch panel, in particular, to a touch panel with discontinuous chain of resistances.
2. Related Art
Nowadays, the most popular touch panels sold in the market are generally classifiable as resistive-type and capacitive-type touch panels. The resistive-type also can be classified into 4-line resistive-type, 5-line resistive-type, 6-line resistive-type and 8-line resistive-type in early days. The capacitive-type can be classified into surface capacitance touch screen (SCT) and projective capacitance touch screen (PCT), which are also referred to as digital-touch technology. The resistive-type and the surface capacitance touch screen (SCT) are generally referred to as analog-touch technology.
The uniform electrical field of conventional analog touch technique is created by the pattern arrangement of the resistor devices around the edges. With production requirements increasing and the booming development of touch panel techniques, the present technique is leading the way in terms of space reduction of the resistor around the edges. Furthermore, it requires a smoother equal potential field, which improves the accuracy of touch panel and may be applied widely.
Please refer to U.S. Pat. No. 6,593,916, entitled a “Touchscreen having multiple parallel connections to each electrode in a series resistor chain on the periphery of the touch area”. It disclosed two ways to improve the ripple effect generated by the frame, as shown in FIG. 1 and FIG. 2. In pattern shown in FIG. 1, the chain of series resistances is formed by the gaps 44 and the series connection of the series electrode 40 on the conducting layer. The spacing between the series electrodes 40 is S, which includes the external part and internal part, for example, the external part 38, 41, 43 and internal part 42. The internal part is formed by every two gaps 44 formed as two insulated gaps 45. One of the insulated gaps 45 is located at the gaps 44 and there is discontinuous resistance 46 between the gap of the insulated gaps 45. The length is approximately equal, the spacing is S′, and the equivalent resistance is shown in FIG. 1B.
Please refer to the pattern shown in FIG. 2A, in which the chain of series resistances is formed by the gaps 54 and the series connection of the series electrode 48, 50 on the conducting layer. The spacing between the series electrodes 40 is S, which includes the external part and internal part. The internal part is formed by every two gaps 54 formed as two insulated gaps 55. Every insulated gap 55 is located at the gaps 54 and there is a discontinuous resistance 56 between the gap of the insulated gaps 55. The length is approximately equal, the spacing is S′, and the equivalent resistance is shown as FIG. 2B.
Please refer to U.S. Pat. No. 2006/0119587, entitled an “Improved electrodes pattern”, as shown in FIG. 3A. The chain of series resistances 145 is formed by the gaps 125 and the series connection of the series electrode 105 on the conducting layer. The series electrode includes an external part 110 and internal part 115. A gap 120 is formed between external part 110 and internal part 115. The internal part 115 is formed by using the way of two insulated gaps 130 formed at every two gaps 125. The discontinuous resistances 145 are located between the insulated gaps 130. The length is approximately equal. To improve the ripple effect, the design of conducting island 150 inserted between the gaps is performed at the gap 125 of series electrodes 105. If the voltage of the discontinuous resistances 145 is VN, VN+1, the voltage of the inserted conducting island 140 is equalized as (VN+VN+1)/2, and the equivalent resistance is shown as FIG. 3B.
Many companies are devoted to the research of the resistor pattern around the edges. However, the improvement of the electrical field of the edge electrodes has yet to be achieved.